JPH10279761A - Aqueous solution containing metal compound for producing electron emission element, production of electron emission element by using the same, electron emission element and image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject aqueous solution capable of providing a coating membrane having a uniform thickness when coated on a substrate after a long- period of storage of the solution by using a liquid consisting essentially of water and further containing a metal compound, a partially esterified polyvinyl alcohol and a buffer. SOLUTION: This aqueous solution contains (A) a metal compound (preferably a water soluble organic metal compound), (B) a partially esterified polyvinyl alcohol, preferably having 5-25 mol.% esterification degree and (C) a buffer, preferably having 6-7 buffering pH. Further, the metal of the component A is preferably platinum, palladium, ruthenium, etc., and concretely the component A is preferably (ammonium) (ethylenediamine) (tetraacetic acid)palladium, etc. The component C preferably contains any one or more of phosphoric acid, acetic acid, boric acid, citric acid and a conjugate base thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous solution containing a metal compound for manufacturing an electron-emitting device, a method for manufacturing an electron-emitting device using the same, an electron-emitting device, and an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, a surface conduction electron-emitting device has been known as a cold cathode electron source. The surface conduction electron-emitting device utilizes a phenomenon in which electron emission occurs when a current flows through a small-area thin film formed on a substrate in parallel with the film surface. As this surface conduction electron-emitting device,
The one using a SnO ₂ thin film by Elinson et al. [M. I. Elinson, Radio Eng. El
electron Phys. , 10, 1290 (196
5)], using an Au thin film [G. Dittmer:
"Thin Solid Films", 9, 317
(1972)], using an In ₂ O ₃ / SnO ₂ thin film [M. Hartwell and C.M. G. FIG. Fons
tad: "IEEE Trans. ED Con
f. , 519 (1975)], and those using a carbon thin film [Hisashi Araki et al .: Vacuum, Vol. 26, No. 1, p. 22, p. 22 (1983)] and the like have been reported.

As a typical device configuration of these surface conduction electron-emitting devices, the above-mentioned M.S. FIG. 14 schematically shows the Hartwell device configuration. In FIG. 1, reference numeral 1 denotes a substrate. 2 and 3 are device electrodes, 4 is a conductive thin film,
The electron emission portion 5 is formed of a metal oxide thin film or the like formed by sputtering in an H-shaped pattern, and is subjected to an energization process called energization forming described later. In the drawing, the element electrode interval L is 0.5 to 1 mm, and W ′ is 0.1 to 1.0 mm. lmm
Is set with

Conventionally, in these surface conduction electron-emitting devices, the electron-emitting portion 5 is subjected to an energization process called energization forming before the conductive thin film 4 is emitted.
It was common to form That is, the energization forming means applying a DC voltage or a very slowly increasing voltage, for example, about 1 V / min., To both ends of the conductive thin film 4 and energizing the conductive thin film 4 to locally destroy, deform or alter the conductive thin film. To form the electron-emitting portion 5 in a high resistance state. In the electron emitting portion 5, a crack is generated in a part of the conductive thin film 4, and electrons are emitted from the vicinity of the crack. The surface conduction type electron-emitting device which has been subjected to the energization forming process is configured to apply a voltage to the above-described conductive thin film 4 and cause a current to flow through the device, thereby causing the above-described electron-emitting portion 5 to emit electrons.

The thin film including the electron-emitting portion is formed of a conductive thin film having a conductive material deposited on an insulating substrate. The conductive material is directly deposited on the insulating substrate by a deposition technique such as evaporation or sputtering. It is known to form. Alternatively, a solution of an organometallic composition is applied and dried, and the organic component is thermally decomposed and removed by heating and baking to form a metal or a metal oxide. Since the latter method does not require a vacuum device for forming an element, it is an advantageous step for forming an element on a large-area substrate.

[0006]

As described above, the metal composition solution used for forming the conductive thin film by applying the metal composition solution to the substrate once and then sintering it by heating is as follows. It is desirable that the film can be formed by being applied to a predetermined position in a predetermined pattern to form a coating film, and to be appropriately wetted on both the metal surface and the insulating substrate surface. In order to achieve these objects, the present inventors have proposed the use of a metal composition characterized by being a liquid containing, for example, water as a main component and a metal compound and partially esterified polyvinyl alcohol.

However, when the metal composition is stored for a long period of time, if the acidity of the metal composition becomes acidic due to the dissolution of an acidic substance such as carbon dioxide in the air into the metal composition, The acid-catalyzed hydrolysis reaction of the contained partially esterified polyvinyl alcohol changes the film-forming ability and the wettability to the substrate, making it difficult to control the device form. Further, even when a basic substance is added to the metal composition to prevent the acid-catalyzed hydrolysis reaction, if the liquidity of the metal composition becomes basic, it is contained in the metal composition as in the case of acidic. The hydrolysis reaction of the partially esterified polyvinyl alcohol proceeds, and it becomes difficult to control the device form as described above.

Accordingly, an object of the present invention is to obtain a coating film having a uniform thickness when applied to a substrate even after storage for a long period of time, and to apply the coating in a pattern without being greatly affected by the material of the substrate surface. Then, an object of the present invention is to provide a metal compound-containing aqueous solution for producing an electron-emitting device, which can provide a coating film having a predetermined pattern. Another object of the present invention is to form a uniform conductive thin film in a predetermined shape using the metal compound-containing aqueous solution in the step of producing a thin film for forming an electron-emitting portion,
An object of the present invention is to provide a method of manufacturing an electron-emitting device having stable characteristics and an image forming apparatus.

[0009]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that the use of a liquid containing water as a main component, a metal compound, a partially esterified polyvinyl alcohol, and a buffering agent is used. When the emission element is made, the wettability to the substrate is good and the thickness of the coating film is uniform,
By heating and baking this metal compound, a metal compound solution capable of forming a conductive thin film having a uniform thickness was found, and the present invention was completed.

That is, the present invention is characterized in that the metal compound-containing aqueous solution for producing an electron-emitting device is a liquid containing water as a main component and containing a metal compound, partially esterified polyvinyl alcohol, and a buffer. is there.

According to the present invention, there is provided a method for manufacturing an electron-emitting device, comprising the steps of: applying a metal compound-containing aqueous solution between the electrodes; And baking the aqueous solution. The metal compound-containing aqueous solution is a metal compound-containing aqueous solution for producing an electron-emitting device according to any one of claims 1 to 8.

Further, the present invention provides, as an image forming apparatus, an electron source provided with an electron-emitting device obtained by the method of manufacturing an electron-emitting device of the present invention, and a means for applying a voltage to the device.
The light-emitting device includes a light-emitting body that emits light by receiving electrons emitted from the electron-emitting device, and a drive circuit that controls a voltage applied to the electron-emitting device based on an external signal.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an aqueous metal compound solution for manufacturing an electron-emitting device according to the present invention will be described. The metal compound used in the present invention is a water-soluble metal compound, is not particularly limited as long as it is a metal compound that is stably present in a liquid in the presence of a buffer, for example, a metal halide compound, a nitrate compound, Metal salts or metal complexes such as nitrite compounds, ammine complexes and organic amine complexes are suitable, especially organic metal compounds because of their ease of firing.

Examples of the organometallic compounds include metal complex compounds. Specific examples of the complex compound include ethylenediaminetetraacetic acid (EDT).
A) Salt, nitrilotriacetic acid (NTA) salt, trans-
1,2-diaminocyclohexane-N, N, N ', N'
Chelate compounds such as tetraacetic acid (CyDTA) salt are preferably used because of their high complex stability constants and the stability of the solution.

The metal element of the organometallic compound used in the present invention includes platinum group elements such as platinum, palladium and ruthenium, gold, silver, copper, chromium, tantalum, iron, tungsten, lead, zinc, tin and the like. Can be used.

The above-mentioned aqueous solution of the metal compound applied to the substrate for forming the conductive film for the electron-emitting portion used in the present invention contains water as a main component and the above-mentioned metal compound and partially esterified polyvinyl alcohol. Liquid.

The partially esterified polyvinyl alcohol is a polymer containing a vinyl alcohol unit and a vinyl ester unit. For example, commonly available "fully" hydrolyzed polyvinyl alcohol can be converted to various acylating agents,
That is, a polymer obtained by partial esterification with a carboxylic anhydride such as acetic anhydride or a carboxylic anhydride such as acetyl chloride is a partially esterified polyvinyl alcohol. In the normal polyvinyl alcohol production process, that is, in the production of polyvinyl alcohol by hydrolysis of polyvinyl acetate, the so-called partially hydrolyzed polyvinyl alcohol obtained without stopping the hydrolysis of polyvinyl acetate during the reaction and not completely hydrolyzing is also used. It also corresponds to partially esterified polyvinyl alcohol. From the viewpoint of availability and cost, this partially hydrolyzed polyvinyl alcohol is most useful as the partially esterified polyvinyl alcohol used in the present invention.

As the acyl group forming the ester, an acyl group derived from an aliphatic carboxylic acid such as a propionyl group, a butyroyl group and a stearoyl group can be used in addition to the acetyl group already described above. These acyl groups need to have 2 or more carbon atoms. On the other hand, no clear limit is found on the upper limit of the number of carbon atoms of the acyl group that can be used in the present invention, and it has been proved at least experimentally that an acyl group having 18 carbon atoms is effective.

Since the degree of esterification of the partially esterified polyvinyl alcohol affects the film forming ability and the wettability to the substrate, the esterification rate is 5 mol% to 25 mol.
%, More preferably 8%.
mol% to 22 mol%.

The term "esterification ratio" as used herein refers to the ratio of the number of bonded acyl groups to the total number of vinyl alcohol repeating units in the polymer, and is quantified by means such as elemental analysis or infrared absorption analysis. be able to.

The liquid metal compound aqueous solution applied to the substrate for forming the electron emitting portion conductive film used in the present invention contains water as a main component, the above metal compound, partially esterified polyvinyl alcohol and a buffer. Is a liquid containing

The above-mentioned buffering agent has an effect of keeping the pH of the metal composition liquid constant when the acid or base is added to the aqueous solution of the metal compound even when the acid or base is added to the metal composition liquid.
It is a composition having a buffering action.

The buffer pH range of the above buffer is 6 to 7
Is desirably within the range. The ester hydrolysis reaction proceeds whether it is acidic or basic, but the acid catalyzes the hydrolysis reaction, whereas the base causes the stoichiometric hydrolysis reaction. Therefore, the hydrolysis reaction rate constant is larger in the basic hydrolysis reaction, so that the progress of the hydrolysis reaction is slower than neutral rather than slightly acidic.
That is, it is necessary to control the liquid property so that the pH is in the range of 6 to 7.

Examples of the buffer used in the present invention include a mixture of a salt of a weak acid such as phosphoric acid, acetic acid, boric acid, citric acid and a strong base thereof, or N,
N-bis (2-hydroxyethyl) 2-aminoethanesulfonic acid, imidazole, 3- (N-morpholino) -2
-Hydroxypropanesulfonic acid, piperazine N, N '
-Bis (2-ethanesulfonic acid), N- (2-acetamido) -2-aminoethanesulfonic acid, N- (2-acetamido) iminodiacetic acid, bis (2-hydroxyethyl) imino-tris (hydroxymethyl) Compounds having a weakly basic group and a strongly acidic group in a molecule such as methane can be exemplified.

After coating the above-mentioned aqueous solution of the metal compound on an insulating substrate to form a coating film, the organic component is decomposed and eliminated by drying and baking as described later to form a conductive thin film on the substrate. As the coating means, conventionally known liquid coating means such as dipping, spin coating, spray coating and the like can be used. In particular, if an aqueous solution of a metal compound, which is a liquid containing water as a main component and containing a metal compound and partially esterified polyvinyl alcohol, is used, a homogeneous coating film can be easily formed almost without depending on the material of the substrate to be applied or the application means. And a uniform conductive thin film.

Usually, for the purpose of producing an electron-emitting device, it is necessary to form the conductive thin film at a predetermined position on a substrate in a predetermined shape. As a method of partially forming such a conductive thin film, a method of once forming a conductive thin film on a substrate and then removing an unnecessary portion to leave the conductive thin film only at a predetermined position or the above-described metal compound coating method is used. A method of forming an electroconductive thin film only at a predetermined position by removing unnecessary coating portions after forming a film on a substrate and then heating and baking, or applying the metal compound aqueous solution only at a predetermined position on the substrate Then, a method of forming a conductive thin film only at a predetermined position by heating and firing can be used.

The step of applying the metal compound aqueous solution only to a predetermined position on the substrate may be a step of using a conventionally known liquid applying means such as dipping, spin coating, spray coating or the like through a mask. However, a step of applying a droplet of the aqueous solution of the metal compound only to a predetermined position on the substrate without using a mask may be employed.

The means for applying the droplets of the aqueous metal compound solution to the substrate may be any method as long as the droplets can be formed and applied. An ink jet system that can generate and provide good controllability is convenient. Ink jet systems generate droplets by mechanical impact such as piezo elements,
There is a bubble jet method in which the liquid is heated by a micro heater or the like and droplets are generated by bumping, and in any case, micro droplets of about 10 nanograms to several tens micrograms are generated with good reproducibility on the substrate. Can be granted.

In the droplet applying step, it is not always necessary to apply the droplet only once to the same position on the substrate, but the droplet is applied a plurality of times to give a desired amount of the metal compound aqueous solution on the substrate. You may. When the droplets are applied independently on the substrate, a small coating film having a circular shape or a shape close thereto is generally formed on the substrate. However, it is possible to form a continuous large coating film of any shape by shifting the application position on the substrate to a position separated by a distance smaller than the diameter of the circle and applying a plurality of droplets.

The metal compound aqueous solution applied to the substrate by the above means is dried and fired to form a conductive inorganic fine particle film, thereby forming an inorganic fine particle film for emitting electrons on the substrate. Note that the fine particle film described here is a film in which a plurality of fine particles are aggregated, and not only in a state where fine particles are individually dispersed and arranged microscopically, but also in a state where fine particles are adjacent to each other or overlap each other (including an island shape). Point the membrane. The particle diameter of the fine particle film means the diameter of the fine particles whose particle shape can be recognized in the above state.

In the drying step, natural drying, blast drying, heat drying and the like may be used. The liquid-coated substrate is placed in an electric dryer at 70 ° C. to 130 ° C., for example, for 30 minutes.
It can be dried by putting it for about 2 to 2 minutes. The baking step may use a heating means that is usually used. The firing temperature should be a temperature sufficient to decompose the organometallic compound to form inorganic fine particles.
0 ° C or more and 500 ° C or less. For firing, any of a reducing gas atmosphere, an oxidizing gas atmosphere, an inert gas atmosphere, and a vacuum can be used. Under reducing or vacuum conditions, metal fine particles are often generated by thermal decomposition of the organometallic compound. On the other hand, under oxidizing conditions, metal oxide fine particles are often generated. However, the firing atmosphere and the oxidation state of the produced fine particles are not simply determined as described above. For example, even in the firing step under an oxidizing gas atmosphere, the first thing generated by the decomposition of the organometallic compound is metal fine particles, and the metal is oxidized by continuing the firing and the metal oxide is formed. In some cases, fine particles are generated. Regardless of what is produced, whether it is a metal or a metal oxide, it can be used for the electron-emitting device of the present invention as long as it forms a conductive fine particle film. From the viewpoint of simplification of the firing apparatus and reduction of the manufacturing cost, the firing step performed in an air atmosphere is excellent. The optimum firing time varies depending on the type of the organometallic compound used, the firing atmosphere and the firing temperature, but is usually about 2 to 40 minutes. The firing temperature may be constant, but may be changed according to a predetermined program. The drying step and the firing step need not necessarily be performed as separate steps, and may be performed simultaneously and continuously.

The aqueous solution containing the metal compound applied to the substrate by the above means is converted into a conductive inorganic fine particle film through a drying and baking step, thereby forming a conductive thin film for electron emission on the substrate. The fine particle film described here is a film in which a plurality of fine particles are aggregated, and the fine structure is such that the fine particles are individually dispersed and arranged or the fine particles are adjacent to each other.
Alternatively, they are in an overlapping state (including a case where some fine particles are aggregated to form an island structure as a whole). The particle size of the fine particles ranges from several Angstroms to several thousand Angstroms, preferably from 10 to 20 Angstroms.
0 angstrom range. In this specification, the term “fine particles” is frequently used, and the meaning will be described.

Small particles are called "fine particles", and smaller ones are called "ultra fine particles". It is widely practiced to call a “cluster” smaller than “ultrafine particles” and having a few hundred atoms or less. However, each boundary is not strict and changes depending on what kind of property is focused on. Also "fine particles"
And "ultrafine particles" may be collectively referred to as "fine particles", and the description in this specification is in line with this.

"Experimental Physics Course 14, Surface / Particle"
(Edited by Kinoshita Yoshio, Kyoritsu Shuppan, published September 1, 1986) states as follows. "When we say fine particles in this paper, their diameter is about 2-3 μm to 10 nm.
Up to about 10 nm, especially when it is referred to as ultrafine particles.
It means from about m to about 2 to 3 nm.
It is not exactly strict because both are collectively written as fine particles, but it is a rough guide. A particle is referred to as a cluster when the number of atoms constituting the particle is two to several tens to several hundreds "(page 195, lines 22 to 26).
In addition, the definition of "ultra-fine particles" in the "Hayashi / Ultra-fine Particle Project" of the New Technology Development Corporation has the lower limit of the particle size, as follows.

In the "Ultra Fine Particle Project" of the Creative Science and Technology Promotion System (1981 to 1986), a particle having a size (diameter) in the range of about 1 to 100 nm is called "ultra fine particle". Then, one ultrafine particle is about 100-
It is an aggregate of about 10 ⁸ atoms. Ultra-fine particles are large to giant particles on an atomic scale. ("Ultrafine Particles-Creative Science and Technology", Hayashi Tax, Ryoji Ueda, Akira Tazaki; Mita Publishing, pp. 2-4, 1988) "Even smaller than ultrafine particles, that is, several to several hundred atoms." A single particle composed of individual particles is usually called a cluster ”(p. 2, lines 12 to 13). Based on the general terminology as described above, the term “fine particles” in the present specification is an aggregate of a large number of atoms and molecules, and the lower limit of the particle size is about several angstroms to about 10 angstroms, and the upper limit is about several microns. It refers to things.

In the drying step, natural drying, blast drying, heat drying and the like may be used. The baking step may use a heating means that is usually used. The drying step and the firing step do not necessarily need to be performed as separate and distinct steps, and may be performed continuously or simultaneously.

If the electron-emitting conductive thin film is formed according to the above-described method, the droplet can be selectively applied only to an arbitrary portion on the substrate in the droplet applying step. Therefore, the conventional process in which an organic metal or the like is applied to the entire surface of the substrate and baked and then unnecessary portions of the conductive inorganic fine particle film are removed by applying photolithography technology can be replaced with a simple and low-cost process. Furthermore, a uniform conductive thin film can be produced without crystal precipitation or the like in the step of forming the electron emission portion.

Next, a method of manufacturing a surface conduction electron-emitting device according to a preferred embodiment of the present invention will be described. Here, an electron-emitting device having a planar structure will be described, but the manufacturing method of the present invention is not limited to manufacturing a flat-type electron-emitting device.

FIG. 1 is a schematic plan view and a sectional view showing the structure of a basic surface conduction electron-emitting device suitable for the present invention. The basic configuration of a basic electron-emitting device suitable for the present invention will be described with reference to FIG. In FIG. 1, 1 is a substrate, 2 and 3 are device electrodes, 4 is a conductive thin film, and 5 is an electron emitting portion. As the substrate 1, quartz glass, glass having a reduced content of impurities such as Na, blue plate glass, a glass substrate obtained by laminating SiO ₂ formed on blue plate glass by a sputtering method or the like, and ceramics such as alumina are used.

The material of the opposing device electrodes 2 and 3 is as follows.
A general conductor material is used, for example, Ni, Cr, Au,
A printed conductor composed of a metal or alloy such as Mo, W, Pt, Ti, Al, Cu, Pd and a metal or metal oxide such as Pd, Ag, Au, RuO ₂ , Pd-Ag and glass; It is appropriately selected from a transparent conductor such as In ₂ O ₃ —SnO ₂ and a semiconductor material such as polysilicon.

Element electrode interval (L), element electrode length (W)
The shape and the like of the conductive thin film 4 are appropriately designed depending on the form to be applied. The element electrode interval (L) is preferably from several hundred angstroms to several hundreds of micrometers, and more preferably from several micrometers to several tens of micrometers depending on the voltage applied between the element electrodes.

The length (W) of the device electrode is preferably from several micrometers to several hundred micrometers depending on the resistance value and electron emission characteristics of the electrode, and the film thickness d of the device electrodes 2 and 3 is preferably several hundreds. A few micrometers from Angstrom. In addition to the structure shown in FIG. 1, a conductive thin film 4 and opposing element electrodes 2 and 3 may be stacked on the insulating substrate 1 in this order.

The conductive thin film 4 is particularly preferably a fine particle film composed of fine particles in order to obtain good electron emission characteristics. The thickness of the conductive thin film 4 depends on the step coverage of the device electrodes 2 and 3 and the gap between the device electrodes 2 and 3. The resistance is appropriately set in accordance with the resistance value and the energization forming conditions described later, and is preferably from several Angstroms to several thousand Angstroms, particularly preferably from 10 Angstroms to 500 Angstroms, and the resistance value is from the square of 10 to 10 7. It is a sheet resistance value of square ohm / square.

The electron-emitting portion 5 is a high-resistance crack formed in a part of the conductive thin film 4 and depends on the thickness, film quality, and material of the conductive thin film 4 and a manufacturing method such as energization forming described later. Formed. In addition, the crack may have conductive fine particles having a particle size of several Angstroms to several hundred Angstroms. The conductive fine particles are similar to some or all of the elements of the material forming the conductive thin film 4. Further, the electron emitting portion 5 and the conductive thin film 4 in the vicinity thereof may contain carbon and a carbon compound.

There are various methods for manufacturing the above-mentioned surface conduction electron-emitting device, and one example is schematically shown in FIG. Hereinafter, the manufacturing method will be described in order with reference to FIGS. In FIG. 2, FIG.
1 are given the same reference numerals as those given in FIG.

1) The substrate 1 is sufficiently washed with a detergent, pure water, an organic solvent, and the like, and after the element electrode material is deposited by a vacuum deposition method, a sputtering method, or the like, the substrate 1 is formed on the substrate 1 by using, for example, a photolithography technique. The device electrodes 2 and 3 are formed (FIG. 2A).

2) A metal compound solution is applied to the substrate 1 provided with the device electrodes 2 and 3 to form a metal compound thin film.
As a means for coating, a usual aqueous solution coating means such as spin coating, dipping, spray coating or the like can be used. Further, as another application means, a droplet applying means represented by an ink jet such as a piezo method or a heat foaming (bubble jet) method can be used (FIG. 2B). Thereafter, the above-mentioned coating film is heated and fired to decompose organic components, thereby obtaining a conductive thin film 4 (FIG. 2C). In order to form the conductive thin film 4 into a desired planar shape, an unnecessary portion may be removed by performing a patterning process such as lift-off or etching laser trimming before or after heating and baking the coating film.
When an appropriate droplet applying means is used, a coating film having a desired conductive thin film pattern can be formed, and in this case, the patterning process can be omitted.

The above-mentioned liquid droplet applying means means that an aqueous solution is
This is a means for applying a small droplet having a size of 0 μm or less and 1 μm or more, and using one or a plurality of droplets on the surface to be coated. Ink-jet is a droplet applying means for forming the above-mentioned aqueous solution droplets, ejecting them toward the surface to be coated, and transferring the liquid droplets to the surface to be coated mainly by inertia of the liquid droplets. Normally, the above-mentioned ink jet is a means for changing a relative position between a droplet emitting unit and a surface to be coated, and a liquid droplet being transferred due to the inertia for the purpose of transferring a liquid droplet to a desired position on the surface to be coated. In many cases, means for adjusting the flight direction of the liquid droplet by applying an external force due to non-contact such as static electricity to the droplet is also used.

The piezo method is an ink-jet method in which a deformation force generated when a voltage is applied to a piezoelectric body is used to form and eject liquid droplets. The bubble jet method is one type of ink jet, and uses a bumping force generated when a liquid is heated in a small space to form and eject liquid droplets.

When the metal compound thin film coated as described above is heated and baked, the organic component is usually decomposed at 1000 ° C. or less, and in most cases around 300 ° C., and inorganic compounds such as metals and metal oxides, or those compounds are decomposed. The composition changes to a composition in which a simple organic substance having a small carbon number is adsorbed on the surface. Usually, the conductive thin film formed as described above has a microscopic form in which a large number of fine particles in which several to thousands of metal atoms contained in a metal-containing aqueous solution are aggregated.

3) Subsequently, an energization process called energization forming is performed. As an example of a method of the forming step, a method by an energization process will be described. Device electrode 2,
When a current is applied under a suitable degree of vacuum using a power source (not shown) between the three, an electron emitting portion 5 having a changed structure is formed at the portion of the conductive thin film 4 (FIG. 2D). ). According to the energization forming, a portion where the structure of the conductive thin film 4 is locally changed such as destruction, deformation or alteration is formed. This portion constitutes the electron emission section 5.

FIG. 4 shows an example of the voltage waveform of the energization forming. The voltage waveform is particularly preferably a pulse waveform. For this purpose, the method shown in FIG. 4A for continuously applying a pulse with a constant pulse peak value and the method shown in FIG. 4B for applying a voltage pulse while increasing the pulse peak value are used. is there. First, when the pulse crest value is a constant voltage, FIG.
Will be described.

T1 and T2 in FIG. 4A are the pulse width and pulse interval of the voltage waveform. Normally T1 is 1 μsec ~
10 ms and T2 are set in the range of 10 μs to 100 ms. The peak value of the triangular wave (peak voltage at the time of energization forming) is appropriately selected depending on the form of the surface conduction electron-emitting device, and is applied for several seconds to several tens of minutes at an appropriate degree of vacuum. Under such conditions, for example, a voltage is applied for several seconds to several tens minutes. Note that the pulse waveform applied between the electrodes of the element is not limited to a triangular wave, and a desired waveform such as a rectangular wave can be adopted. T1 and T2 in FIG.
Can be the same as that shown in FIG.
Peak value of triangular wave (peak voltage during energization forming)
Is increased in steps of, for example, about 0.1 V and applied under an appropriate vacuum atmosphere.

The end of the energization forming process in this case can be detected by applying a voltage that does not locally destroy or deform the conductive thin film 4 during the pulse interval T2, and measuring the current. . For example, an element current flowing by applying a voltage of about 0.1 V is measured, and a resistance value is obtained. When the resistance value indicates 1 M ohm or more, the energization forming is terminated.

4) It is preferable to perform a process called an activation step on the device after the forming. The activation step means that the element current If and the emission current Ie are
This is a process that changes significantly.

The activation step can be performed, for example, by repeating the application of a pulse in an atmosphere containing an organic substance gas, similarly to the energization forming. This atmosphere can be formed by using an organic gas remaining in the atmosphere when the inside of the vacuum vessel is evacuated using, for example, an oil diffusion pump or a rotary pump, or a vacuum once sufficiently evacuated by an ion pump or the like. It can also be obtained by introducing a gas of an appropriate organic substance therein. The preferable gas pressure of the organic substance at this time varies depending on the above-described application form, the shape of the vacuum vessel, the type of the organic substance, and the like, and is appropriately set according to the case. Examples of suitable organic substances include aliphatic hydrocarbons such as alkanes, alkenes, and alkynes, aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, and organic acids such as phenol, carboxylic acid, and sulfonic acid. Specifically, methane,
Saturated hydrocarbons represented by C _n H _{2n + 2} such as ethane and propane; unsaturated hydrocarbons represented by a composition formula such as C _n H _{2n + 2} such as ethylene and propylene; benzene, toluene, methanol, ethanol and formaldehyde , Acetaldehyde, acetone, methyl ethyl ketone, methylamine, ethylamine, phenol, formic acid, acetic acid, propionic acid and the like can be used. By this treatment, carbon or a carbon compound is deposited on the device from the organic substance existing in the atmosphere, and the device current If and the emission current Ie are significantly changed.

The end of the activation step is determined as appropriate while measuring the device current If and the emission current Ie. The pulse width, pulse interval, pulse crest value, and the like are set as appropriate.
Carbon and carbon compounds include graphite (including so-called highly oriented pyrolytic carbon HOPG, pyrolytic carbon PG, and amorphous carbon GC. HOPG is a crystal structure of almost perfect graphite, and PG is a crystal having a crystal grain of about 200 mm. The structure is slightly disturbed, GC refers to a crystal having a crystal grain of about 20 angstroms and the disorder of the crystal structure is further increased), amorphous carbon (amorphous carbon and a mixture of amorphous carbon and microcrystals of the above graphite) The thickness is preferably in the range of 500 angstroms or less.

5) The electron-emitting device obtained through the above steps is preferably subjected to a stabilization step. This step is a step of exhausting the organic substance in the vacuum container. It is preferable to use a vacuum exhaust device that does not use oil so that the oil generated from the device does not affect the characteristics of the element. Specifically, a vacuum exhaust device such as a sorption pump or an ion pump can be used.

In the activation step, when an oil diffusion pump is used as an exhaust device and an organic gas derived from an oil component generated from the oil diffusion pump is used, it is necessary to keep the partial pressure of this component as low as possible. The partial pressure of the organic component in the vacuum vessel is preferably 1 × 10 ⁻⁸ Torr or less, and more preferably 1 × 10 ⁻⁸ Torr or less.
Particularly preferred is ^-10 Torr or less. Further, when evacuating the inside of the vacuum vessel, it is preferable to heat the entire vacuum vessel to facilitate evacuating the organic substance molecules adsorbed on the inner wall of the vacuum vessel and the electron-emitting device. The heating conditions at this time are 80 ~
It is desirable that the heating time is 200 ° C. for 5 hours or more, but the conditions are not particularly limited, and the conditions are appropriately selected depending on various conditions such as the size and shape of the vacuum vessel and the configuration of the electron-emitting device. The pressure in the vacuum vessel must be as low as possible.
~ 3 × 10 ^-7 Torr or less, more preferably 1 × 10 ^-7 Torr
^-8 Torr or less is particularly preferred.

It is preferable that the atmosphere at the time of driving after performing the stabilizing step is the same as the atmosphere at the end of the stabilizing treatment. However, the present invention is not limited to this. If the organic substance is sufficiently removed, Even if the degree of vacuum itself is slightly reduced, sufficiently stable characteristics can be maintained. By adopting such a vacuum atmosphere, the deposition of new carbon or carbon compound can be suppressed, and as a result, the device current If and the emission current I
e becomes stable.

The basic characteristics of the electron-emitting device suitable for the present invention prepared by the above-described device configuration and manufacturing method will be described with reference to FIGS. FIG.
1 is a schematic configuration diagram of a measurement evaluation device for measuring the electron emission characteristics of an element having the configuration shown in FIG. 3, the same parts as those shown in FIG. 1 are denoted by the same reference numerals as those shown in FIG. Reference numeral 30 denotes an ammeter for measuring the device current If flowing through the conductive thin film 4 between the device electrodes 2 and 3, and reference numeral 34 denotes an anode electrode for capturing the emission current Ie emitted from the electron emission portion of the device. 33 is a high voltage power supply for applying a voltage to the anode electrode 34, 32 is an ammeter for measuring the emission current Ie emitted from the electron emission portion 5 of the device, and 35 is a vacuum device.

The electron-emitting device and the anode 3
4 and the like are installed in a vacuum device 35, and the vacuum device is provided with equipment necessary for a vacuum device such as an exhaust pump (not shown) and a vacuum gauge, and can perform measurement and evaluation of the element under a desired vacuum. It has become. Therefore, in this measurement device,
The steps after the energization forming described above can also be performed. The voltage of the anode electrode is 1 kV to 10 kV, and the distance H between the anode electrode and the electron-emitting device is 2 mm to 8 mm.
It measured in the range of.

FIG. 5 shows a typical example of the relationship between the emission current Ie, the device current If, and the device voltage Vf measured using the measurement and evaluation apparatus shown in FIG. FIG. 5 shows the emission current Ie.
Is significantly smaller than the element current If, and is shown in arbitrary units.

As is apparent from FIG. 5, the surface conduction electron-emitting device suitable for the present invention has three characteristic characteristics with respect to the emission current Ie. That is, first, the emission current Ie of the present element rapidly increases when an element voltage higher than a certain voltage (referred to as a threshold voltage, Vth in FIG. 5) is applied. Current Ie is hardly detected. That is, it is a nonlinear element having a clear threshold voltage Vth with respect to the emission current Ie.

Second, since the emission current Ie depends monotonically on the device voltage Vf, the emission current Ie can be controlled by the device voltage Vf. Third, the emission charge captured by the anode electrode 34 depends on the time during which the device voltage Vf is applied. That is, the amount of charge captured by the anode electrode 34 can be controlled by the time during which the device voltage Vf is applied.

As will be understood from the above description, an electron source having a plurality of electron emission elements arranged in accordance with an input signal due to the characteristic characteristics of the surface conduction electron emission element suitable for the present invention. In addition, it is possible to easily control even an image forming apparatus or the like, and it is possible to apply to various fields.

Next, an electron source and an image forming apparatus suitable for the present invention will be described. By arranging a plurality of surface conduction electron-emitting devices suitable for the present invention on a substrate, an electron source or an image forming apparatus can be constructed.

In the method of arranging the electron-emitting devices on the substrate, for example, a large number of surface-conduction type electron-emitting devices described in the conventional example are arranged in parallel, and both ends of each device are connected by wiring, and A large number of rows of emission elements are arranged (referred to as row direction),
In a direction perpendicular to the wiring (referred to as a column direction), a control electrode (also referred to as a grid) provided in a space above the electron source controls and drives the electrons from the electron-emitting devices in a ladder-like arrangement. An n-type Y-directional wiring is provided on the m-type X-directional wiring described above through an interlayer insulating layer, and the X-directional wiring and the Y-directional wiring are respectively connected to a pair of electron electrodes of the electron-emitting device. Can be This is hereinafter referred to as a simple matrix arrangement. First, the simple matrix arrangement will be described in detail.

According to the above-mentioned three characteristics of the basic characteristics of the electron-emitting device according to the present invention, even in the electron-emitting devices arranged in a simple matrix, the electrons emitted from the electron-emitting devices are not higher than the threshold voltage. It is controlled to the peak value and the width of the pulse-like voltage applied between the opposing element electrodes. On the other hand, below the threshold voltage, almost no electrons are emitted. According to this characteristic, even when a large number of electron-emitting devices are arranged, an arbitrary electron-emitting device can be selected by appropriately applying the pulse voltage to each device, and the amount of electron emission can be controlled. You can do it.

Hereinafter, the configuration of an electron source based on this principle will be described with reference to FIG. 6, reference numeral 61 denotes an electron source substrate, 62 denotes an X-direction wiring, 63 denotes a Y-direction wiring, 64 denotes an electron-emitting device, and 65 denotes a connection. Note that the electron-emitting device 64 may be a device manufactured by the above-described manufacturing method of the present invention, and may be either a flat type or a vertical type.

In the figure, the electron source substrate 61 is the above-mentioned glass substrate or the like, and its size and thickness are determined by the number of electron-emitting devices provided on the electron source substrate 61 and the design shape of each device. In the case where a part of the container is used when the electron source is used, it is set as appropriate depending on conditions for keeping the container at a vacuum.

The m X-directional wires 62 are DX1, DX2,
... Made of DXm, and is a conductive metal or the like formed on the electron source substrate 61 by a vacuum deposition method, a printing method, a sputtering method, or the like. Further, the material, the film thickness, the wiring width, and the like are appropriately set so that a substantially uniform voltage is supplied to many electron-emitting devices.
The Y-direction wiring 63 is composed of n wirings DY1, DY2,... DYn, and is created in the same manner as the X-direction wiring 62.
An interlayer insulating layer (not shown) is provided between the m x-directional wirings 62 and the n y-directional wirings 63, and electrically separated to form a matrix wiring. Both m and n are positive integers. The interlayer insulating layer (not shown) is formed by vacuum evaporation,
SiO ₂ formed by printing method, sputtering method, etc.
The insulating substrate 61 on which the directional wirings 62 are formed is formed in a desired shape on the entire surface or a part thereof.
The material and the production method are appropriately set. The X-direction wiring 62 and the Y-direction wiring 63 are drawn out as external terminals.

Further, in the same manner as described above, the electron-emitting device 6
4 opposing electrodes (not shown) are provided with m X-direction wirings 62.
And n n-directional wirings 63 are electrically connected by a connection 65 made of a conductive metal or the like formed by a vacuum evaporation method, a printing method, a sputtering method, or the like.

Here, m X-directional wires 62 and n Y wires
The conductive metal of the element electrode facing the directional wiring 63 and the connection 65 may have some or all of the same or different constituent elements, and may be appropriately selected from the above-described material of the element electrode and the like. You. Note that the wirings to these device electrodes may be collectively referred to as device electrodes when the device electrode and the wiring material are the same. The electron-emitting device is provided on the substrate 61.
Alternatively, it may be formed on any of the interlayer insulating layers (not shown).

As will be described in detail later, the X-direction wiring 62 is not shown for applying a scanning signal for scanning a row of the electron-emitting devices 64 arranged in the X-direction in accordance with an input signal. Are electrically connected to the scanning signal generating means.

On the other hand, in the Y-direction wiring 63, each of the rows of the electron-emitting devices 64 arranged in the Y-direction is provided in accordance with an input signal.
It is electrically connected to a modulation signal generating means (not shown) for applying a modulation signal for modulation. Further, the driving voltage applied to each element of the electron-emitting device is supplied as a difference voltage between a scanning signal and a modulation signal applied to the element.

In the above configuration, individual elements can be selected and driven independently only by simple matrix wiring. Next, an image forming apparatus used for display by an electron source having a simple matrix arrangement created as described above will be described with reference to FIGS. 7, 8, and 9. FIG. 7 is a basic configuration diagram of a display panel of the image forming apparatus, FIG. 8 is a fluorescent film, and FIG. 9 is a block diagram of a driving circuit in which the image forming apparatus performs display according to an NTSC television signal.

In FIG. 7, reference numeral 61 denotes an electron source substrate on which an electron-emitting device is manufactured as described above, and 71 denotes an electron source substrate.
1, a face plate having a fluorescent film 74 and a metal back 75 formed on the inner surface of a glass substrate 73; 72, a support frame;
1. The support frame 72 and the face plate 76 are coated with frit glass or the like, and 400 to 5
Seal by baking at 00 degrees for 10 minutes or more.
8.

In FIG. 7, reference numeral 64 corresponds to the electron-emitting portion in FIG. Reference numerals 62 and 63 denote an X-direction wiring and a Y-direction wiring connected to a pair of device electrodes of the electron-emitting device.
As described above, the envelope 78 is constituted by the face plate 76, the support frame 72, and the rear plate 71.
Since the rear plate 71 is provided mainly for the purpose of reinforcing the strength of the substrate 61, if the substrate 61 itself has sufficient strength, a separate rear plate 71 is unnecessary, and the support frame 72 is directly sealed on the substrate 61. The envelope 78 may be constituted by the face plate 76, the support frame 72, and the substrate 61. Furthermore, the face plate 76, the rear plate 71
By installing a support (not shown) called a spacer between them, the configuration of the envelope 78 having sufficient strength against the atmospheric pressure can be obtained.

FIG. 8 shows a fluorescent film. The fluorescent film 74 is made of only a phosphor in the case of monochrome, but is a black conductive material 8 called a black stripe or a black matrix depending on the arrangement of the phosphor in the case of a color fluorescent film.
1 and a phosphor 82. Black stripe,
The purpose of providing the black matrix is to make the color separation between the phosphors 82 of the three primary color phosphors necessary for color display black so that color mixing and the like become inconspicuous, and to reflect external light on the phosphor film 74. Is to suppress a decrease in contrast due to The material of the black stripe is not limited to a commonly used material containing graphite as a main component, as long as it is conductive and has little light transmission and reflection. The method of applying the phosphor on the glass substrate 73 is not limited to monochrome or color, and a precipitation method or a printing method is used.

A metal back 75 is usually provided on the inner side of the fluorescent film 74. The purpose of the metal back is to improve the brightness by mirror-reflecting the light emitted from the phosphor toward the inner surface side to the face plate 76 side, to act as an electrode for applying an electron beam acceleration voltage, This is to protect the phosphor from damage due to collision of negative ions generated in the enclosure. The metal back can be produced by performing a smoothing process (usually called filming) on the inner surface of the phosphor film after producing the phosphor film, and then depositing Al by vacuum deposition or the like.

The face plate 76 further includes a fluorescent film 7.
A transparent electrode (not shown) may be provided on the outer surface side of the fluorescent film 74 in order to increase the conductivity of the fluorescent film 74. When performing the above-mentioned sealing, in the case of color, the phosphors of each color must correspond to the electron-emitting devices, so that it is necessary to perform sufficient alignment.

The envelope 78 passes through an exhaust pipe (not shown) and
And the sealing is performed. Further, a getter process may be performed to maintain the degree of vacuum after sealing the envelope 78. This is because the getter arranged at a predetermined position (not shown) in the envelope 78 is heated by a heating method such as resistance heating or high-frequency heating immediately before or after the envelope 78 is sealed. This is a process for forming a deposited film. Getter is usually Ba
Are the main components, and maintain a degree of vacuum of, for example, 1 × 10 −5 or 1 × 10 −7 [Torr] by the adsorption action of the deposited film. Steps after the forming of the electron-emitting device are appropriately set.

Next, referring to the block diagram of FIG. 9, a schematic configuration of a driving circuit for performing a television display based on an NTSC television signal in a display panel configured using electron sources in a simple matrix arrangement will be described. explain. 91 is the display panel, 92 is a scanning circuit, 93 is a control circuit, 94 is a shift register, 95 is a line memory,
96 is a synchronization signal separation circuit, 97 is a modulation signal generator, Vx
And Va are DC voltage sources.

The function of each part will be described below. First, the display panel 91 is connected to an external electric circuit via terminals Dox1 to Doxm, terminals Doy1 to Doyn, and a high voltage terminal Hv. Of these, the terminals Dox1 to Doxm sequentially drive electron sources provided in the display panel, that is, a group of electron-emitting devices arranged in a matrix of M rows and N columns, one row at a time (N elements). A scanning signal is applied to the scan.

On the other hand, to the terminals Dy1 to Dyn, a modulation signal for controlling the output electron beam of each of the electron-emitting devices in one row selected by the scanning signal is applied. Further, a DC voltage of, for example, 10 K [V] is supplied to the high voltage terminal Hv from the DC voltage source Va, which has sufficient energy to excite the phosphor into an electron beam output from the electron-emitting device. Is an accelerating voltage for giving

Next, the scanning circuit 92 will be described. This circuit includes M switching elements inside (in the drawing, S1 to Sm are schematically shown), and the switching elements include an output voltage of a DC voltage source Vx or 0 [V] (ground). Level)
It is electrically connected to the terminals Dx1 to Dxm of the display panel 91. Each of the switching elements S1 to Sm operates based on the control signal Tscan output from the control circuit 93. However, in practice, it can be easily configured by combining switching elements such as FETs. In the case of the present embodiment, the DC voltage source Vx uses a drive voltage applied to an unscanned element based on the characteristics (electron emission threshold voltage) of the electron emission element. It is set to output a constant voltage that is equal to or lower than the voltage.

The control circuit 93 has a function of matching the operations of the respective units so that an appropriate display is performed based on an externally input image signal. A synchronization signal Tsyn sent from a synchronization signal separation circuit 96 described below.
Based on c, Tscan and Tsft for each part
And Tmry control signals.

The synchronizing signal separating circuit 96 is a circuit for separating a synchronizing signal component and a luminance signal component from an NTSC television signal input from the outside. As is well known, a frequency separating (filter) is used. If a circuit is used, it can be easily configured. The synchronization signal separated by the synchronization signal separation circuit 96 is composed of a vertical synchronization signal and a horizontal synchronization signal as is well known, but here, for convenience of explanation,
This is shown as a Tsync signal. On the other hand, a luminance signal component of an image separated from the television signal is referred to as a DATA signal for convenience, and the signal is input to a shift register 94.

The shift register 94 is for serially / parallel-converting the DATA signal input serially in time series for each line of an image, and is based on a control signal Tsft sent from the control circuit 93. Works. (That is, the control signal Tsft may be rephrased as the shift clock of the shift register 94.) The data of one line of the serial-parallel-converted image (corresponding to the drive data of the N-electron emitting elements) is , I
It is output from the shift register 94 as N parallel signals of d1 to Idn.

The line memory 95 is a storage device for storing data for one line of an image for a required time only.
The contents of Id1 to Idn are stored as appropriate according to the control signal Tmry sent from the control circuit 93. The stored contents are output as I'd1 to I'dn and input to the modulation signal generator 97. The modulation signal generator 97
A signal source for appropriately driving and modulating each of the electron-emitting devices in accordance with each of the image data I'd1 to I'dn. An output signal of the signal source is supplied to a terminal Doy1 to Doyn. Applied to the device.

As described above, the electron-emitting device according to the present invention has the following basic characteristics with respect to the emission current Ie. That is, as described above, electron emission has a clear threshold voltage Vth, and electron emission occurs only when a voltage higher than Vth is applied. For a voltage equal to or higher than the electron emission threshold, the emission current also changes according to the change in the voltage applied to the element. Note that the value of the electron emission threshold voltage Vth and the degree of change of the emission current with respect to the applied voltage may be changed by changing the material, configuration, and manufacturing method of the electron emission element. Something like that can be said. That is, when a pulse-like voltage is applied to this element, for example, an electron emission does not occur even when a voltage lower than the electron emission threshold is applied, but when a voltage higher than the electron emission threshold is applied, an electron beam is output. You. At that time, first, it is possible to control the intensity of the output electron beam by changing the peak value Vm of the pulse. Second, it is possible to control the total amount of charges of the output electron beam by changing the pulse width Pw.

Accordingly, as a method of modulating the electron-emitting device in accordance with the input signal, there are a voltage modulation method, a pulse width modulation method, and the like. A voltage modulation circuit that generates a voltage pulse of a certain length but modulates the peak value of the pulse appropriately according to input data is used.

In order to implement the pulse width modulation method,
As the modulation signal generator 97, a pulse width modulation type circuit that generates a voltage pulse having a constant peak value and appropriately modulates the width of the voltage pulse according to input data is used.

By the series of operations described above, television display can be performed using the display panel 91. still,
Although not specifically described in the above description, the shift register 9
The line memory 95 and the line memory 95 may be of a digital signal type or an analog signal type. In short, the serial / parallel conversion and storage of the image signal may be performed at a predetermined speed.

When the digital signal type is used, it is necessary to convert the output signal DATA of the synchronizing signal separating circuit 96 into a digital signal. This can be easily achieved by providing an A / D converter at the output of the 96. Needless to say, In connection with this, the modulation signal generator 97 determines whether the output signal of the line memory 95 is a digital signal or an analog signal.
It is needless to say that the circuit used for the above is slightly different. That is, in the case of a digital signal, in the case of the voltage modulation method, for example, a well-known D / A conversion circuit may be used as the modulation signal generator 97, and an amplification circuit or the like may be added as necessary. In the case of the pulse width modulation method, the modulation signal generator 97 is, for example, a high-speed oscillator, a counter for counting the number of waves output from the oscillator, and a comparison for comparing the output value of the counter with the output value of the memory. Those skilled in the art can easily configure the circuit by using a circuit in which devices (comparators) are combined. If necessary, an amplifier for voltage-amplifying the pulse-width-modulated signal output from the comparator to the drive voltage of the electron-emitting device may be added.

On the other hand, in the case of an analog signal, in the case of a voltage modulation method, an amplification circuit using, for example, a well-known operational amplifier may be used as the modulation signal generator 97. If necessary, a level shift circuit or the like may be used. May be added. In the case of the pulse width modulation method, for example, a well-known voltage-controlled oscillation circuit (VCO) may be used. If necessary, an amplifier for amplifying the voltage up to the drive voltage of the electron-emitting device may be added. Is also good.

In the image display device suitable for the present invention completed as described above, the external terminals Dox1 to Doxm, Doy1 to Doy are connected to the respective electron-emitting devices.
n, electrons are emitted by applying a voltage, and a high voltage is applied to the metal back 75 or a transparent electrode (not shown) through the high voltage terminal Hv, thereby accelerating the electron beam and causing the electron beam to collide with the fluorescent film 74 to excite the electron beam. An image can be displayed by emitting light. The configuration described above is a schematic configuration necessary for manufacturing a suitable image forming apparatus used for display and the like. For example, detailed portions such as materials of each member are not limited to those described above. Appropriate selection is made to suit the use of the device. As an input signal example, NTS
Although the C method was given, it is not limited to this, but PAL, S
Various systems such as the ECAM system may be used, and a TV signal composed of a larger number of scanning lines (for example, MUSE) may be used.
And other high-definition TV) systems.

Next, the above-mentioned ladder-shaped arrangement of the electron source and the image forming apparatus will be described with reference to FIGS.
In FIG. 10, reference numeral 100 denotes an electron source substrate; 101, an electron-emitting device; and 102, Dx1 to Dx10, common wirings for wiring the electron-emitting devices. Electron-emitting device 10
A plurality of 1s are arranged on the substrate 100 in parallel in the X direction. (This is called an element row). A plurality of the element rows are arranged and serve as an electron source. By appropriately applying a drive voltage between the common wires of each element row, each element row can be driven independently. That is, a voltage equal to or higher than the electron emission threshold may be applied to an element row that wants to emit an electron beam, and a voltage equal to or lower than the electron emission threshold may be applied to an element row that does not emit an electron beam. Also, the common wiring Dx2 between each element row
Dx9, for example, Dx2 and Dx3 may be the same wiring.

FIG. 11 is a view showing the structure of a display panel of an image forming apparatus having a ladder-type electron source.
110 is a grid electrode, 111 is a hole through which electrons pass, 112 is Dox1, Dox2. . . Doxm outer terminals 113 are connected to the grid electrodes 110, G1, G2. . . Outer container terminal made of Gn, 114
Is an electron source substrate in which the common wiring between the element rows is the same as described above. 7 and 10 indicate the same components. A major difference from the image forming apparatus having the simple matrix arrangement (shown in FIG. 7) is that the electron source substrate 1
Grid electrode 110 between
It is equipped with.

A grid electrode 110 is provided between the substrate 100 and the face plate 76. The grid electrode 110 is capable of modulating the electron beam emitted from the electron-emitting device. In order to allow the electron beam to pass through a stripe-shaped electrode provided orthogonal to the ladder-shaped arrangement of the element rows, , A circular opening 111 is provided one by one. The shape and the installation position of the grid are not necessarily those shown in FIG. 11, and a large number of passage openings may be provided in a mesh shape as openings, and may be provided, for example, around or near the electron-emitting device.
The terminal 112 outside the container and the terminal 113 outside the grid container
It is electrically connected to a control circuit (not shown).

In this image forming apparatus, a modulation signal for one line of an image is simultaneously applied to the grid electrode rows in synchronization with the sequential driving (scanning) of the element rows one column at a time, so that each electron beam By controlling the irradiation of the phosphor, one image
Can be displayed line by line.

Further, according to the concept of the present invention, an image forming apparatus suitable as a display device of a television conference system, a computer, etc. as well as a display device of a television broadcast is provided. Further, it can be used as an image forming apparatus as an optical printer including a photosensitive drum and the like.

[0104]

EXAMPLES Examples of the present invention will be described below.
The present invention is not limited to the following examples. Example 1 Ammonium palladium ethylenediaminetetraacetate (Pd
2.9 g of EDTA.2NH ₄ ), 0.05 g of 86% saponified polyvinyl alcohol (average degree of polymerization 500), and 25 g of isopropyl alcohol, and 1/15 mol / l.
Phosphate buffer solution (pH 6.4, manufactured by Nacalai Tesque) was added to make the total amount 100 g, to give a palladium compound solution.
When the pH of this solution was measured, the pH at 25 ° C.
Was 6.4. This palladium compound solution was added to 25
After storing for 6 months in a thermostat at ℃, the pH was measured.
The pH at 25 ° C. was 6.4.

Example 2 A 1/15 mol / l Na acetate / acetic acid mixture (molar ratio 1: 100) was used in place of the 1/15 mol / l phosphate buffer used in Example 1, For, a metal compound solution was prepared according to Example 1 and used as a palladium compound solution. When the pH of this solution was measured, the pH at 25 ° C. was 6.2. This palladium compound solution was stored in a thermostat at 25 ° C. for 6 months and the pH was measured. As a result, the pH at 25 ° C. was 6.2.

Example 3 Instead of the 1/15 mol / l phosphate buffer used in Example 1, a 1/15 mol / l Na borate / borate mixture (molar ratio 100: 1) was used. About Example 1
A metal compound solution was prepared according to the procedure described above to obtain a palladium compound solution. When the pH of this solution was measured, the pH at 25 ° C. was 6.8. This palladium compound solution was stored in a thermostat at 25 ° C. for 6 months, and the pH was measured. As a result, the pH at 25 ° C. was 6.8.

Example 4 Instead of the 1/15 mol / l-phosphate buffer used in Example 1, 1/15 mol / l-tri-Na citrate / citric acid mixture
(Molar ratio: 1: 1), and the other conditions were the same as in Example 1 to prepare a metal compound solution, which was used as a palladium compound solution. When the pH of this solution was measured,
Was 6.4. This palladium compound solution was stored for 6 months in a thermostat at 25 ° C., and the pH was measured. As a result, the pH at 25 ° C. was 6.4.

Example 5 A 1/15 mol / l N- (2-acetamido) 2-aminoethanesulfonic acid solution was used instead of the 1/15 mol / l phosphate buffer used in Example 1, and Except for the above, a metal compound solution was prepared according to Example 1 to obtain a palladium compound solution. When the pH of this solution was measured,
The pH at 25 ° C. was 6.5. After storing this palladium compound solution in a thermostat at 25 ° C. for 6 months,
Was measured, the pH at 25 ° C. was 6.5.

Comparative Example 1 A metal compound solution was prepared in the same manner as in Example 1 except that water was used instead of the 1/15 mol / l phosphate buffer used in Example 1, and a palladium compound solution was prepared. And When the pH of this solution was measured, the pH at 25 ° C. was 7.1. This palladium compound solution is
After storing for 6 months in a thermostat at 25 ° C., the pH was measured. As a result, the pH at 25 ° C. was 5.9.

Embodiment 6 This embodiment shows an example of a method of manufacturing the surface conduction electron-emitting device shown in FIGS. A quartz substrate was used as the insulating substrate 1. After sufficiently washing the substrate with an organic solvent, device electrodes 2 and 3 made of Pt were formed on the surface of the substrate 1. The element electrode interval L was 20 μm, the width W of the element electrode was 500 μm, and its thickness d was 1000 Å.

0.55 g of ammonium palladium ethylenediaminetetraacetate (Pd-EDTA.2NH ₄ )
A palladium compound solution was prepared by taking 0.05 g of 6% saponified polyvinyl alcohol (average degree of polymerization 500), 25 g of isopropyl alcohol and 1 g of ethylene glycol, and adding water to make the total amount 100 g. The palladium compound solution was filtered through a membrane filter having a pore size of 0.25 μm, filled in a bubble jet printer head BC-01 of Canon Inc., and a DC voltage of 20 V was externally applied to a predetermined heater inside the head for 7 μsec. Then, a palladium compound solution was discharged into the gap portion between the device electrodes 2 and 3 on the quartz substrate. The ejection was repeated five more times while maintaining the positions of the head and the substrate. The droplet was substantially circular and had a diameter of about 110 μm.

When the substrate was heated at 350 ° C. for 12 minutes to thermally decompose the palladium compound, palladium oxide was formed. The electric resistance between the device electrodes 2 and 3 is 11
kΩ.

Next, a voltage was applied between the device electrodes 2 and 3, and the conductive thin film 4 was formed by conducting (forming). FIG. 4 shows a voltage waveform of the forming process. In FIG. 4, T1 and T2 are the pulse width and pulse interval of the voltage waveform. In this embodiment, T1 is 1 millisecond,
T2 is set to 10 milliseconds, the peak value of the triangular wave (the peak voltage at the time of forming) is set to 5 V, and the forming process is performed by about 1
This was performed for 60 seconds in a vacuum atmosphere of × 10 ^-6 Torr.

The electron-emitting portion 5 thus produced was in a state in which fine particles mainly composed of palladium element were dispersed and arranged, and the average particle diameter of the fine particles was 30 angstroms. The electron emission characteristics of the device fabricated as described above were measured using the measurement and evaluation device shown in FIG.

Also in FIG. 3, 1 is an insulating substrate, 2 and 3 are device electrodes, 4 is a thin film including an electron-emitting portion, 5 is an electron-emitting portion, 31 is a power supply for applying a voltage to the device,
Reference numeral 30 denotes an ammeter for measuring an element current If, 34 denotes an anode electrode for measuring an emission current Ie generated from the element, 33 denotes a high-voltage power supply for applying a voltage to the anode electrode 34, and 32 denotes an emission current. It is an ammeter for measuring. In measuring the device current If and the emission current Ie of the electron-emitting device, the power supply 31 and the ammeter 30 are connected to the device electrodes 2 and 3, and the power supply 33 and the ammeter 32 are connected above the electron-emitting device. The arranged anode electrode 34 is disposed. Further, the electron-emitting device and the anode electrode 34 are installed in a vacuum device, and the vacuum device is provided with equipment necessary for a vacuum device such as an exhaust pump (not shown) and a vacuum gauge. The device can be measured and evaluated below. In this embodiment, the distance between the anode and the electron-emitting device is 4 mm, and the potential of the anode is 1
kV, the degree of vacuum in the vacuum device when measuring the electron emission characteristics is 1 ×
It was set to 10 ^-6 Torr.

The device voltage was applied between the electrodes 2 and 3 of the electron-emitting device using the measurement and evaluation apparatus described above, and the device current If and the emission current Ie flowing at that time were measured. The current-voltage characteristics as shown were obtained. In this device, the emission current Ie rapidly increases from an element voltage of about 7.4 V, and at an element voltage of 16 V, the element current If becomes 2.4 mA, the emission current Ie becomes 1.0 μA, and the electron emission efficiency η = Ie / If ( %) Was 0.04%.

Instead of the anode electrode 34, the above-described face plate having the fluorescent film and the metal back was arranged in a vacuum device. When electron emission from the electron source was attempted in this way, a part of the fluorescent film emitted light, and the intensity of light emission changed according to the device current Ie. Thus, it was found that this element functions as a light-emitting display element.

In the embodiments described above, when forming the electron-emitting portion, the forming process is performed by applying a triangular wave pulse between the electrodes of the device, but the waveform applied between the electrodes of the device is limited to the triangular wave. A desired waveform such as a rectangular wave may be used, and the peak value, pulse width, pulse interval, etc. are not limited to the above-mentioned values, and a desired value is selected if the electron emitting portion is formed well. You can do it.

Example 7 A metal compound solution was prepared by using 1/15 mol / l-phosphate buffer (pH 6.4, manufactured by Nacalai Tesque) in place of water in Example 6, and treated in the same manner as in Example 6. It was discharged in a rectangular shape on the element electrode substrate. The same processing as in Example 6 was performed to produce an electron-emitting device. An electron emission phenomenon was confirmed at a device voltage of 16 V, and the electron emission efficiency was 0.045%.

Example 8 The metal compound solution used in Example 7 was placed in a thermostat at 25 ° C. for 6 hours.
An electron-emitting device was prepared by performing the same treatment as in Example 7 except that the one stored for months was used instead of the metal compound solution of Example 7. An electron emission phenomenon was confirmed at an element voltage of 16 V, and the electron emission efficiency was 0.043%.

Comparative Example 2 The metal compound solution used in Example 6 was treated in a thermostat at 25 ° C.
What was stored for months was used in place of the metal compound solution of Example 6, and discharged in a rectangular shape on the element electrode substrate in the same manner as in Example 6. When the rectangular liquid dries on the substrate, the existing portion of the liquid gradually shrinks, and the diameter is about 70 μm.
The shape of the circle became so. When this substrate was heat-treated in the same manner as in Example 6, a thick conductive film at the center was formed in the circular portion, and almost no conductive film was present around the center.
When forming was attempted, a large current was required, and almost no electron emission was observed even when the device was formed.

Example 9 In the same manner as in Example 7, the solution of the organometallic compound solution was applied to each counter electrode of the substrate (FIG. 6) on which 256 element electrodes of 16 rows and 16 columns and matrix wiring were formed. Drops are applied by a bubble jet type ink jet device,
After firing, a forming process was performed to obtain an electron source substrate. A rear plate 81, a support frame 82,
The face plate 86 was connected and vacuum-sealed to form an image forming apparatus according to the conceptual diagram of FIG. By applying a predetermined voltage to each element in a time-sharing manner through the terminals Dx1 to Dx16 and the terminals Dy1 to Dy16 and applying a high voltage to the metal back through the terminal Hv, an arbitrary matrix image pattern can be displayed.

[0123]

As described above, the metal compound aqueous solution for producing an electron-emitting device according to the present invention, when applied on a substrate, has good wettability of the substrate and uniform thickness of the coating film. By heating and baking this coating film, a conductive thin film having a uniform thickness can be formed, which is particularly effective in the process of manufacturing a thin film for forming an electron-emitting portion of a surface-conduction electron-emitting device.

Further, the aqueous metal compound solution for producing an electron-emitting device of the present invention can maintain these characteristics even when stored for a long period of time. Therefore, the amount of the metal material for forming the electron emission portion can be reduced. According to the method for manufacturing an electron-emitting device using the metal compound aqueous solution for manufacturing the electron-emitting device of the present invention, an electron-emitting portion having an arbitrary shape and size can be easily formed, and free electron emission can be performed. Element design is possible.

As described above, in the electron-emitting device manufactured using the metal compound aqueous solution for manufacturing the electron-emitting device, since the thin film for forming the electron-emitting portion is uniform, a stable product with characteristic characteristics can be obtained at low cost. Thus, a display device using this electron-emitting device can be obtained in a stable manner at a low cost.
Further, an image display device in which a plurality of display elements that are characteristically stable are arranged is a high-quality image display device with stable characteristics and little luminance unevenness.

[Brief description of the drawings]

FIG. 1 is a schematic plan view and a cross-sectional view showing a configuration of a basic surface conduction electron-emitting device of the present invention.

FIG. 2 is an explanatory diagram of a manufacturing process of the surface conduction electron-emitting device of the present invention.

FIG. 3 is a schematic configuration diagram of a measurement evaluation device for measuring electron emission characteristics.

FIG. 4 is an example of a voltage waveform of energization forming suitable for the present invention.

FIG. 5 is a typical example of the relationship between the emission current Ie, the device current If, and the device voltage Vf of the surface conduction electron-emitting device suitable for the present invention.

FIG. 6 is an electron source having a simple matrix arrangement applicable to the present invention.

FIG. 7 is a schematic configuration diagram of a display panel of an image forming apparatus applicable to the present invention.

FIG. 8 is a schematic view illustrating an example of a fluorescent film.

FIG. 9 is a block diagram illustrating an example of a driving circuit for displaying an image forming apparatus according to an NTSC television signal.

FIG. 10 is a schematic view showing an example of an electron source having a ladder arrangement applicable to the present invention.

FIG. 11 is a schematic configuration diagram illustrating an example of a display panel of an image forming apparatus applicable to the present invention.

FIG. 12 is a schematic view showing an example of a conventional surface conduction electron-emitting device.

[Explanation of symbols]

1: substrate, 2: 3: element electrode, 4: conductive thin film, 5: electron emitting portion, 50: ammeter for measuring element current If flowing through conductive thin film 4 between element electrodes 2 and 3; 51 Power supply for applying element voltage Vf to electron-emitting device, 53:
A high-voltage power supply for applying a voltage to the anode electrode 54;
4: Anode electrode for capturing emission current Ie emitted from the electron emission portion of the device, 55: Ammeter for measuring emission current Ie emitted from the electron emission portion of the device, 5
6: vacuum device, 57: exhaust pump, 71: electron source substrate,
72: X direction wiring, 73: Y direction wiring, 74: Surface conduction electron-emitting device, 75: Connection, 81: Rear plate, 8
2: support frame, 83: glass substrate, 84: fluorescent film, 85:
Metal back, 85: face plate, 87: high voltage terminal, 88: envelope, 91: display panel, 92: scanning circuit, 93: control circuit, 94: shift register, 95: line memory, 96: synchronization signal separation circuit , 97: modulation signal generator, Vx and Va: DC voltage source, 100: electron source substrate, 101: electron-emitting device, 102: Dx1 to Dx1
0 is a common wiring for wiring the electron-emitting devices, 1
10: grid electrode, 111: holes for passing electrons, 112: Dox1, Dox2. . . Doxm external terminal 113: G1, G2. . . Outer container terminal made of Gn, 114:
Electron source substrate.

Claims (16)

[Claims] An aqueous solution containing a metal compound for producing an electron-emitting device, which comprises a metal compound, a partially esterified polyvinyl alcohol, and a buffer. 2. The aqueous solution containing a metal compound for manufacturing an electron-emitting device according to claim 1, wherein the metal is one of platinum group elements. 3. The method according to claim 1, wherein the metal is one of platinum, palladium, ruthenium, gold, silver, copper, chromium, tantalum, iron, tungsten, lead, zinc, and tin. Aqueous solution containing a metal compound. 4. The aqueous solution containing a metal compound according to claim 1, wherein the metal compound is a water-soluble organic metal compound. 5. The metal compound-containing aqueous solution according to claim 1, wherein the esterification rate of the partially esterified polyvinyl alcohol is in the range of 5 to 25 mol%. 6. The metal compound-containing aqueous solution according to claim 1, wherein a buffer pH of the buffer is in the range of 6 to 7. 7. The method according to claim 1, wherein the buffer is phosphoric acid, acetic acid, boric acid,
7. The method according to claim 1, wherein at least one of citric acid and a conjugate base thereof is contained.
2. The aqueous solution containing a metal compound according to item 1. 8. The metal compound-containing aqueous solution according to claim 1, wherein the buffer contains at least one of an amino group and a sulfonic acid group in a molecule. 9. A method of manufacturing an electron-emitting device having an electron-emitting portion between opposing electrodes, comprising a step of applying a metal compound-containing aqueous solution between the electrodes, and a step of heating and firing the metal compound-containing aqueous solution; A method for manufacturing an electron-emitting device, wherein the aqueous solution containing a metal compound is the aqueous solution containing a metal compound for manufacturing an electron-emitting device according to any one of claims 1 to 8. 10. The method according to claim 9, wherein the step of applying the metal compound-containing aqueous solution is a step of applying droplets of the metal compound-containing aqueous solution. 11. The method according to claim 10, wherein the step of applying a droplet applies a plurality of droplets to a predetermined position. 12. The step of applying droplets comprises applying a plurality of droplets in close proximity to each other, whereby the metal compound-containing aqueous solution is spread over a wider continuous area than by independently applied droplets. The method for manufacturing an electron-emitting device according to claim 10, wherein the electron-emitting device is provided. 13. The method according to claim 10, wherein the application of the droplet is performed by an ink-jet method. 14. The method according to claim 13, wherein the inkjet method is a bubble jet method. 15. An electron-emitting device manufactured according to the manufacturing method according to claim 9. Description: 16. An electron source comprising: the electron-emitting device according to claim 15; and a voltage applying means for applying voltage to the electron-emitting device.
An image forming apparatus comprising: a luminous body that emits light by receiving electrons emitted from the electron-emitting device; and a driving circuit that controls a voltage applied to the electron-emitting device based on an external signal.